HIMAWARI 8/9 gridded full-disk (FD)data Version 02 (V20190123) release note
HIGUCHI, Atsushi, TAKENAKA, Hideaki, and TOYOSHIMA, Koichi:
Center for Environmental Remote Sensing (CEReS), Chiba University, Japan（Last update: 14 Dec. 2022）
List of Contents
0. HIMAWARI 8 and 9 Observations
1. Introduction
2. Highlights in Version 02 (V20190123)
2.1. Improvements for geo-correction accuracy
2.2. 4-km data release
3. Gridded data specifications
3.1. Data server (anonymous ftp server) and directory structure
3.2. Gridded data specification and the relation between CEReS released gridded data andJMA official HIMAWARI 8/9 AHIʼs bands
3.3. File naming rules
3.3.1. EXT (0.005 degree; approximately 500-m spatial resolution at nadir)
3.3.2. VIS (0.01 degree; approximately 1-km spatial resolution at nadir)
3.3.3. SIR (0.02 degree; approximately 2-km spatial resolution at nadir)
3.3.4. TIR (0.02 degree; approximately 2-km spatial resolution at nadir)
3.3.5. 4KM (0.04 degree; approximately 4-km spatial resolution at nadir) [New!]3.4. Conversion from raw digital number to physical variables, such as Tbb and spectralreflectance3.4.1. Convert from raw digital number to physical variables, such as Tbb, spectralreflectance [New!]
3.4.2. Updating HIMAWARI-8 AHI albedo conversion look-up tables to reflect new
calibration coefficients (EXT, VIS, SIR）
3.4.3. Inter-calibration activities (GSICS)
4. About citation
4.1. About the treatments of the quasi-real-time dataset
Acknowledgments

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0. HIMAWARI 8 and 9 Observations
Observation periods by HIMAWARI 8 and 9 ware as follows:- HIMAWARI 8 Advanced Himawari Imager [AHI]: 07 July 2015 ‒ 0450 UTC 13 Dec
2022, with several times are switch by HIMAWARI 9.
- HIMAWARI 9 AHI: 0250 UTC 13 Feb 2018 ‒ 0710 UTC 14 Feb 2018, 0450 UTC 13 Dec
2022 ‒# Please check observation periods released by JMA.
1. Introduction
CEReS released gridded-processed (latitude-longitude coordinated with geo-correction)
Version 02 (V20190123) dataset of HIMAWARI 8/9 Advanced Himawari Imager (AHI)
Full-Disk (FD) mode. Highlights of updated Version 02 are as follows.
2. Highlights in Version 02 (V20190123)In Version 02 (V20190123) gridded dataset, we apply the technologies for the solar
radiation product “AMATERASS” into a gridded dataset. Specifically, Version 02 improves
geo-correction accuracy and adds 4-km products such as physical variables and geometric
information.
2.1. Improvements for geo-correction accuracy
Version 02 slightly improves the accuracy of geo-correction compared with Version 01(V20151105). Users feel the benefit of using Version 02, particularly EXT utilization (0.005degree) during the daytime. On the other hand, Version 02ʼs geo-correction accuracy during
the nighttime is the same as Version 01.
2.2. 4-km data release
We add the 4-km datasets, containing already converted physical variables and solarsensor zenith and azimuth angles geometric information (see section 3.3.5.).
3. Gridded data specifications
3.1. Data server (anonymous ftp server) and directory structure
In the same manner as Version 01, users can get data files to access the anonymous ftpserver (ftp://hmwr829gr.cr.chiba-u.ac.jp/). After anonymous login, please change directory
to gridded/FD/V20190123/. Alternatively, users can also access directly2ftp://hmwr829gr.cr.chiba-u.ac.jp/gridded/FD/V20190123/. There are sub-directories
named with the following conventions.
YYYYMM YYYY: Year (4 digits), MM: Month（always ２ digits）; e.g., August 2015 -->201508．Each YYYYMM directory has five sub-directories as below.
EXT VIS SIR TIR 4KM

Gridded data specifications stored in each sub-directory will describe in 3.3.3.
3.2. Gridded data specification and the relation between CEReS released gridded data andJMA official HIMAWARI 8/9 AHIʼs bands
Our gridded data has different bands naming rule with JMA official Himawari 8/9 bands
names. Tables 1 and 2 show the relation between our gridded data and JMA's Himawari 8/9
bands, and the common specifications for EXT, VIS, SIR, and TIR.
Table 1: Relation between CEReS gridded data and JMAʼs Himawari 8/9 AHI bands.
CEReS gridded JMA AHI bands

Pixel x Line

Gridded spatial resolution

EXT

24000 x 24000

0.005 degree

12000 x 12000

0.01 degree

6000 x 6000

0.02 degree

6000 x 6000

0.02 degree

VISSIRTIR

01

Band 03 (0.64μm)

01Band 01 (0.47μm)

02Band 02 (0.51μm)

03Band 04 (0.86μm)

01Band 05 (1.6μm)

02Band 06 (2.3μm)

01Band 13 (10.4μm)

02Band 14 (11.2μm)

03Band 15 (12.4μm)

04Band 16 (13.3μm)

05Band 07 (3.9μm)

06Band 08 (6.2μm)

07Band 09 (6.9μm)

08Band 10 (7.3μm)

09Band 11 (8.6μm)

10Band 12 9.6μm)

3Table 2: Common specifications of gridded dataset for EXT, VIS, SIR, and TIR.
Covered area

85E ‒ 205E (155W), 60N ‒ 60S

Data type2 byte “unsigned short” binary data without any hearder andfooter information, with “big endian” byte order.

Data writing orders

West to East (left to right) and North to South (up to down)

Stored data

Himawari Standard (HS) data themselves (CCT count like).
Note that missing-data pixels are filled by the value of 65535 as
the exception.

3.3. File naming rules
File name specifications are as follows; YYYYMMDDHHMN.XXX.ZZ.fld.geoss.bz2
YYYY: Year (4 digits), e.g., Year of 2015 -> 2015.
MM: Month (always 2 digits), e.g., August -> 08.
DD: Day (always 2 digits), e.g., 12th -> 12.
HH: Hour (always 2 digits; Unit is UTC), e.g., 02 UTC -> 02.
MN: Minute (always 2 digits; Unit is UTC), e.g., 10 minutes -> 10.
Note that the timestamp in the file name represents "observation start time (start time toscan)".

XXX: CEReS gridded data wavelength-divided list. i.e., ext, vis, sir, and tir.
Note that those are all capital (EXT, VIS, SIR, and TIR) in the sub-directory names, but aresmall letters in filenames.
ZZ: CEReS gridded band number as listed in Table 1 (always 2 digits). fld: FD version.
geoss: no meaning. Simply following the CEReS geostationary gridded data's name rule.
3.3.1. EXT (0.005 degree; 500-m at nadir)
Table 3 shows EXT (0.005 degree, 500-m) specifications and file naming rule.
Table 3: EXT gridded data specifications and file naming rule
CEReS gridded

JMA AHI band

Pixel x Line

Gridded spatial resolution

EXT

Band 03 (0.64μm)

24000 x 24000

0.005 degree (500 m at01nadir)4File Name：YYYYMMDDHHMN.ext.01.fld.geoss.bz2．
YYYY: Year (4 digits), MM: Month (always 2 digits), DD: Day (always 2 digits), HH:Hour (always 2 digits; Unit is UTC), MN: Minute (always 2 digits; Unit is UTC)，ext:
CEReS grided data ʻextʼ represented，01: CEReS gridded data band number (01 only forEXT)，geoss: no meaning，bz2: bzip2 compressed file．
Only for the EXT, static information for geo-correction are recorded in the log files
YYYYMMDDHHMN.ext.(coff or loff).fld.txt.bz2. Normally do not need to see these files.
3.3.2. VIS (0.01 degree; 1-km at nadir)
Table 4 shows VIS (0.01 degree, 1-km) specifications and file naming rule.
Table 4: VIS gridded data specifications and file naming rule
CEReS gridded JMA AHI bands
VIS

01

Band 01 (0.47μm)

02Band 02 (0.51μm)

03Band 04 (0.86μm)

Pixel x Line

Gridded spatial resolution

12000 x 12000

0.01 degree (1-km at nadir)

File Name：YYYYMMDDHHMN.vis.ZZ.fld.geoss.bz2．
YYYY: Year (4 digits), MM: Month (always 2 digits), DD: Day (always 2 digits), HH:Hour (always 2 digits; Unit is UTC), MN: Minute (always 2 digits; Unit is UTC)，vis:
CEReS grided data ʻvisʼ represented，ZZ: CEReS gridded data VIS band number (thus01, 02, and 03)，geoss: no meaning，bz2: bzip2 compressed file.
3.3.3. SIR (0.02 degree; 2-km at nadir)
Table 5 shows SIR (0.02 degree, 2-km) specifications and file naming rule.
Table 5: SIR gridded data specifications and file naming rule
CEReS gridded JMA AHI bands
SIR01

Band 05 (1.6μm)

02Band 06 (2.3μm)

Pixel x Line

Gridded spatial resolution

6000 x 60000.02 Degree (2-km at nadir)

File Name：YYYYMMDDHHMN.sir.ZZ.fld.geoss.bz2．
YYYY: Year (4 digits), MM: Month (always 2 digits), DD: Day (always 2 digits), HH:
Hour (always 2 digits; Unit is UTC), MN: Minute (always 2 digits; Unit is UTC)，sir:
CEReS grided data ʻsirʼ represented，ZZ: CEReS gridded data SIR band number (thus 01and 02)，geoss: no meaning，bz2: bzip2 compressed file.

53.3.4. TIR (0.02 degree; 2-km at nadir)
Table 6 shows TIR (0.02 degree, 2-km) specifications and file naming rule.
Table 6: TIR gridded data specifications and file naming rule
CEReS gridded JMA AHI bands

TIR

01

Band 13 (10.4μm)

02Band 14 (11.2μm)

03Band 15 (12.4μm)

04Band 16 (13.3μm)

05Band 07 (3.9μm)

06Band 08 (6.2μm)

07Band 09 (6.9μm)

08Band 10 (7.3μm)

09Band 11 (8.6μm)

10Band 12 9.6μm)

Pixel x Line

Gridded spatial resolution

6000 x 6000

0.02 Degree (2-km at nadir)

File Name：YYYYMMDDHHMN.tir.ZZ.fld.geoss.bz2．
YYYY: Year (4 digits), MM: Month (always 2 digits), DD: Day (always 2 digits), HH:Hour (always 2 digits; Unit is UTC), MN: Minute (always 2 digits; Unit is UTC)，tir:
CEReS grided data ʻtirʼ represented，ZZ: CEReS gridded data TIR band number (thusfrom 01 to 10)，geoss: no meaning，bz2: bzip2 compressed file.
3.3.5. 4KM (0.04 degree) [New!]
4KM data is Version 02ʼs new product. 4KM data stored in daily sub-directories such as;
ftp://hmwr829gr.cr.chiba-u.ac.jp/gridded/FD/V20190123/YYYYMM/4KM/
YYYYMMDD/．4KM data specifications and file naming rules are represented in Table 7.
Table ７：4KM data specifications and file naming rule
(a: common specification)
Pixel x Line, resolution 3000 x 3000, 0.04 degree (4-km at nadir)
Covered area
Data type
Data writing orders
Stored data

85E ‒ 205E (155W), 60N ‒ 60S (same as the other dataset)
4 byte “float” binary data with “big endian” byte order.

West to East (left to right) and North to South (up to down)
Already converted to physical variables

6(b: EXT, VIS, SIR, TIR physical variables converted dataset)
File name example

Physical variable

YYYYMMDDHHMN.xxx.ZZ.rad.fld.4km.bin.bz2 (xxx: ext,ext, vis, sir, tir irradiancevis, sir, tir; ZZ: CEReS gridded data band number)(unit: W m-2 sr-1 μm-1)

YYYYMMDDHHMN.xxx.ZZ.rfc.fld.4km.bin.bz2 (xxx: ext,ext, vis, sir spectral

vis, sir; ZZ: CEReS gridded data number)
YYYYMMDDHHMN.xxx.ZZ.rfy.fld.4km.bin.bz2 (xxx: ext,vis, sir; ZZ: CEReS gridded data number)reflectance (dimensionless)ext, vis, sir spectralreflectance (%)

YYYYMMDDHHMN.tir.ZZ.tbb.fld.4km.bin.bz2 (ZZ:tir (only) brightness

CEReS gridded data number)

temperature (Tbb (K))(c: geometries dataset)
Filename example

Physical variables

YYYYMMDDHHMN.sun.azm.fld.4km.bin.bz2 Solar azimuth angle (Degree, South
direction is zero, clockwise rotation)
YYYYMMDDHHMN.sun.zth.fld.4km.bin.bz2

Solar zenith angle (Degree)YYYYMMDDHHMN.sat.azm.fld.4km.bin.bz2

Sensor azimuth angle (Degree, South
direction is zero, clockwise rotation)

YYYYMMDDHHMN.sat.zth.fld.4km.bin.bz2

Sensor zenith angle (Degree)YYYYMMDDHHMN.grd.time.mjd.hms.fld.

Scanning time（Normalized 0 to 1, i.e.,4km.bin.bz2

12:00 UTC is 0.5）

YYYYMMDDHHMN.lat.fld.4km.bin.bz2

Latitude (Degree)YYYYMMDDHHMN.lng.fld.4km.bin.bz2

Longitude (Degree)YYYYMMDDHHMN.cap.flg.fld.bin.bz2*1

Cloud flag (Daytime and over ocean
only. More than 1 represents cloud)*1: only cap.flg is consists of 2-byte unsigned short binary with big endian byte order.
3.4. Conversion from raw digital number to physical variables, such as Tbb and spectralreflectance
Except for the 4KM product, the conversion process will be needed to get physicalvariables, using he calibration tables of which produced by JMA.
3.4.1. Conversion from raw digital number to physical variables, such as Tbb and spectralreflectance [New!]7

We provide sample programs (Fortran90, C, and python codes) and calibration tables.
The programs are compressed in a tarball, count2tbb_v103.tgz, and can be download at
ftp://hmwr829gr.cr.chiba-u.ac.jp/gridded/FD/support/.
Version 103 sample programs are that add LUT for HIMAWARI 09 from version 102. If
you already have version 102 or older sample programs, please switch version 103. PC-based
OS such as Windows, Intel MacOS, and Linux (i386, x86_64), standard binary data reading
order is little-endian. Thus, before processing our sample programs, the user needs to byte
swapping process. In the case of Linux, dd command can do such byte swap process asfollows;$dd if=(input binary) of=(output binary) conv=swab
Such a byte swap does not need native 64bit environments such as Power PC, Intel Itanium(IA-64), SPARC, HP-UX, etc.
[Note] Even though 64bit OS on Intel/AMD CPU, such as Linux x86_64, MacOS, andWindows 64-bit, our sample programs for EXT (24000 pixels x 24000 lines) band dataprocess the data as followings;a) The input data file splitting into two files as the Northern area and Southern area.
b) Then C/F90 program convert CCT to reflectance for each splitting file.
c) After the conversion, two files are merged into one. (please see the detail processes inshell scripts in the tarball) This process is mainly due to the limitation of malloc (memoryallocation).
Moreover, under the 32-bit OS, due to 32-bit OS (limitation of 32-bit), it is impossible togenerate any file larger than 2-GB. If users try to analyze EXT data on 32-bit OS, the users
need to treat EXT physical converted data as split files (e.g., Northern and Southern areas).
If you want to read more detail on reading gridded data, the below URL is maybe useful.
http://quicklooks.cr.chiba-u.ac.jp/~himawari_movie/rd_gridded.html
In addition, our gridded data user made Python sample codes. These programs are out of
our support, but maybe useful. https://github.com/zxdawn/Himawari-8-gridded
3.4.2. Updating HIMAWARI-8 AHI albedo conversion look-up tables to reflect new
calibration coefficients (EXT, VIS, SIR）
CEReS look-up tables (LUTs) are based on the original calibration coefficients. Due tosensor degradation of the AHI, JMA's Meteorological Satellite Center (MSC) updates AHI
calibration coefficients annually. Professor MIURA, Tomoaki of the University of Hawai'icreated new LUTs to reflect these new calibration coefficients. If the user analyzes the long8

term trend, it is better to apply these LUTs. Through Professor Miura's courtesy, we canrelease updated LUTs for EXT, VIS, and SIR bands Updated_LUTs_20200308_zip.zip.
Useful reference：Update of Calibration Information Used to Correct Himawari-8 AHI
Sensitivity Trend（https://www.data.jma.go.jp/mscweb/en/oper/eventlog/Update_of_Calibration_Informati
on_2020.pdf; accessed on 03 September 2020）.
3.4.3. Inter-calibration activities (GSICS)
Global Space-based Inter-Calibration System (GSICS) is one of the space components of
the World Meteorological Organization (WMO). Its mission is to provide users with highquality and inter-calibrated measurements from operational satellites. JMA MSC
operationally has been providing information about inter-calibration results at Himawari
Calibration Portal:
https://www.data.jma.go.jp/mscweb/en/oper/calibration/calibration_portal.html(accessed on 01 September 2020)
4. About citation
Please cite two papers listed as below．
Geo-correction algorithm：Takenaka, H., T. Sakashita, A. Higuchi, T. Nakajima (2020):Development of geolocation correction for geostationary satellite observation by phase onlycorrelation method using visible channel, Remote Sensing, 12 (15), 2472,
doi:10.3390/rs12152472.
Geo-correction accuracy validation：Yamamoto, Y., K. Ichii, A. Higuchi, H. Takenaka(2020): Geolocation accuracy assessment of Himawari-8/AHI imagery for application toterrestrial monitoring, Remote Sensing, 12 (9), 1372, doi:10.3390/rs12091372.
Besides, please describe below sentence in Acknowledgements; "Himawari 8/9 gridded

data are distributed by the Center for Environmental Remote Sensing (CEReS), Chiba
University, Japan." CEReS Himawari 8/9 gridded data is limited for non-commercial use.
This data policy is the same as JMA's one for academic-data-releasement. We also prohibit
the distribution of our gridded data to third parties, except among the researchcommunities.
4.1. About the treatments of the quasi-real-time dataset
Due to the data policy of JMA, quasi-real-time data (in the definition of JMA, real-time9data is within 24 hours data since now) cannot open without any restriction. Thus, in theCEReS ftp server, we control the access for quasi-real-time data by IP address. If the user
wants to access quasi-real-time data for non-commercial use only, please send an e-mail withthe accessed global IP address and its objective to below e-mail address.
request4himawaridata _AT_ ceres.cr.chiba-u.ac.jp. We have no plan to change theconfiguration on the CEReS ftp server by user registration. We will do via IP based
restriction only.
Acknowledgments
This activity is partly supported by the Virtual Laboratory (VL) project funded by theMinistry of Education, Culture, Sports, Science and Technology (MEXT), Japan,JST/CREST TEEDA, and the President leaderships of Chiba University. We thank Prof.
HAMADA, Atsushi of University of Toyama, who pointed out our sample programs bug andcontributed to sample programs improvements. Thanks are extended to Prof. MIURA,Tomoaki of the University of Hawai'i who created new LUTs to reflect these new calibration
coefficients. We also thank Mr. LIU, Zhiyan, Ph.D student of Ichii Lab., CEReS, ChibaUniversity, who improved python code in a sample programs package.

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